@KingsArmourer
1) Nope, I call it slicking others call it glassing. Casing is another whole process. Casing is getting the moisture content in the leather right for tooling or other work. The old way was to soak leather in water until bubbles stopped coming out. Then wrap it in a wool blanket and leave overnight. Next morning the moisture content was about right for working. The moisture content is about right when the normal color starts coming back into the leather. This is the time to slick the leather too.
2) Saves ya the overnight wait. I dampen leather with a sponge using my water/Pro Carv mix and when the color starts coming back, which is just a few minutes, I'm good to go. I feel it also assists in uniform moisture content, so that one part of the project is not damper than another as long as you apply it correctly. helps in tooling, wet molding, folding leather etc. I have not dampened or wet a piece of leather without Pro Carv in years.
3) Don't know ya'd have to experiment. Ya could check the temp of the toaster oven with a meat thermometer. Since I wrote this tutorial we've replaced our stove. I now have a dual oven to play with. It rocks.
4) I apply the Quick Slik with a foam brush to the edge of the leather. The lathe just does the rubbing for me. Yep your piece of antler has been used to rub edges for centuries. I use to use an old awl handle that was some unknown hardwood to rub edges.
Ya bet and hope that helps.